Add PyInstaller background freezing and easier reuse

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PyInstaller adds significant latency overhead for complex jobs. For jobs that are often rerun it is useful to re-use the pyinstaller outputs; however, this has to be done manually by specifying the frozen tar path. It would be helpful to have a module that makes freezing in batch (in the background) and re-using frozen tar files easy.

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One possibility is to allow persistent pyinstaller working folders as it reuses some of the work internally.